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Jan. 2, 1923. 1,440,546;

F. C. LANGENBERG ET AL.

FURNACE. FILED APR. '14. 192:. a SHEETS-SHEET 1.

J an. 2, 1923.

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FURNACE.

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Jan. 2, 1923. 1,440,546.

- F. 0. LANGENBERG ET AL.

FURNACE. FILED APR. 14. 1921. 3 SHEETS-SHEET 3 Patented Jan. 2, 1923.

UNITED STATES v p 1,440,54 PATENT OFFICE.

FREDERICK C. LANGENBERG OF XVATERTOVJN, MASSACHUSETTS, AND JOHN'F.FETTERLY, OF ALTOONA, PENNSYLVANIA, ASSIGNOBS TO THE SURFACECO1V.[BU'S'1"IO1\T CO INCORPORATED, OF NEW YORK, N.'Y., A CORPORATION OFNEW YORK.

FURNACE.

Application filed April 14, 1921. Serial No. 461,401.

To all whom it may concern Be it known that we, Fnnnnnron G. LAN-GENBERG and JOHN F. FETTERLY, citizens of the United States, residing,respectively, at Vatertown, county of Middlesex, and State ofMassachusetts, and Altoona, county of Blair, and State of Pennsylvania,have invented certain new and useful Improvements in Furnaces, fullydescribed and represented in the following specification and theaccompanying drawings, forming apart of the same. I i

This invention relates tofurnaces' for differential heating and has foran object to provide for maintaining different parts of the objecttreated at different temperatures. The invention aims to improvefurnaces heretofore used for this'purpose by eliminating heat convectionbetween the zones of different te1n1; eratures and so defining the zonesmore sharply than has heretofore been possible. i y

A further object of the invention is to provide means for changin theposition and extent of the zones of differential treatment withoutaltering the; combustion chambers of the furnace.

A further object of the invention is to adapt a furnace to differentialheating of objects of various size 7 A still further object of theinvention is to provide meansfor definitely fixing thc position of thezones of treatment in rela tion to the object treated.

Vhile the invention may be used in various types of furnaces. we will.for the sake i of example, describe the application of it to a type ofdifferential heating furnace which has been used in the heat treatmentof armor Fig. 4-. is a top view and 5 is. a.

view of the cover plate;

Fig. 6 is a top viewof' the central portion of the upper partition;

Fig. 7 is a side view of the lower diaphragm used in the hardeningoperation looking in a direction parallel to the section plane of Fig.2; y

Fig. 8 is a top view and Fig. 9 a side view of the lower diaphragm usedin the drawing operation;

Fig. 10 is a central vertical section and Fig. 11. a top view of theadapter; and

Fig. 12 is a top View of the water receptacle.

The furnace is cylindrical and its side wall 10 may be composed of thebrick covered by insulating material 11 and a metal shell 12. Within thechamber formed by the side wall 10 is a checkered cylindrical wall 13which extends from the bottom to the top of the furnace and divides itinto an outer annular chamber and an inner cylindrical chamber. Theouter annular chamber is divided into a plurality of heating chambers14, 15 and 16 by horizontal separator walls or partitions l7, l8.Burners 20 are provided. for heating the heating chambers. At the bottomof the inner cylindrical ortreat ing chamber is a water receptacle 21.

The parts of the furnace thus far described were in use prior to themaking of the invention herein claimed. In such furnaces a. differentdegree of heat was pro duc'ed in each of the heating chambers 14:, and16. As eachchamber was in free communication through the checkered wallwith a portion of the treating chamber, different temperatures wereproduced in different parts of the. treating chamber. As however freeconvectionot heat took place I in the space between a shell suspended inthe treating chamber and the checkered wall there were no clearlydefined zones of diff'erent temperatures. In so far as zonesof differingtemperatures were produced the location as well as the general extentfofthe zones were determined by the position of the par ltions 1T 18 whichformed a permanent part of the furnace.

The present invention aims to provlde for 'moresharply defining thezones of different temperatures in the treating chamber and for varyingthe relative extent of such zones.

For this purpose, one ormore removable .diaphragms or dividing membersare pro- (ill .which are fixed in the furnace.

vided l'or liyidinothe space between the wall oi the trez ting chamberand the object being treated into the required number of zones. andthese diaphragrnis are made removable so that by the use of diilerentdiaphragnis suitably formed the relative extent of thesereraldii'l'erent zones may be varied without otherwise changing the :lurnacestructure. The diaphragms are formed with a central opening of suitablesize and shape so that the inner edge will extend closely about theobject to be treated;

In the embodiment of the invention shown, the partitions l7, 18 areextended inwardly through the checkered or other toraininous wall 13 sothat their inner portions form a part of this wall and their inner edgesprovide ledges extending into the treating chamber upon which a e seatedannular diaphragms 25, 26. The diameter of the central opening in thesediaphragg is is only slightly larger than that ol the shell to betreatedfso that while the LlliLPllI'Zl Z IZHS do not interfere with theplacing of the shell in the furnace or the rotation of during treatment,they substantially prerent conrection of heat between the zones whichthey form in the treating chamber. Furthermore, the diaphragms may be,and in some cases are, so formed that the zones of differenttemperatures at the surface of the shell under treatment do notcorrespond with the position of the partitions 17, 15 5 [is shown inFig. 2. the lower diaphragm is termed to extend upwardly within thechamber so that its inner edge will surround the shell in a planesubstantially above that of the partition 18, thereby increasing; theextent of the lower heating zone and decreasing that of the next upperzone. When the diaphragm is so extended in the direction longitudinal ofits axis, its longitudinally eX tending portion between its outer andinner edges should. be oi such diameter as to lie spaced outward fromthesurfacc of the ob feet to be treated and spared inwa from the chamberwall.

Seated upon a ledge 3i at ilie. t p treating chamber is a similar diapiragg i which has a central. opening: s illicicn large to permit theinsortioi'i of the shell. the treating chamber. over plates 2H and 29are proyided for closing this opening in the diaphragm 2'7 and thussubslautially preventing the escape of heat fro-in the top of the upperzone.

The diaphramis 2b, 2'? are all removable. The top diaphragm :37 has acircuin'lt'erential flange 30 which. rests upon the ledge 31 at the topof the treating chamher. This ledge 3i extends outwardly from thesurface otthe wall of the treating chamber and the top opening 32 of thefurnace J greate ri -m t r than the ti s shell at various dili'erenl;

18 and extendin into the treating chainher.- The segmental flanges 3eare ada atczl to pass between the ends of the segmental ledges of thepartition 17 so that the diaphragm 26 may he lifted out of the "chamber.

For use in place of: the shown in 2, other d' to thesev but having cent:a diiierent diametermay be adapt the furnace to the treatment or shellsof different diameter. in adoitioin other dia 'ihragms may be providedwhich arc so formed that their inner eiliges surround the a erticaldistai'u-es from the partitions with which their outer peripheries arealigned. Thus, any desired arran rrnient 0; the position an extent ofthe mines of treatment of. the shell ma be secured without altering theext nt or .1 1 o, combustion than. n i is .i is shown a diaphragm 25which may be Sill/ ill stituted for the diaphragm shown 2. The diaphragmhas flanges similar the flanges diaphragm 25, but its general shat larto that of the diaphragm 26 i it is used the upper limit of the lowestZone of treatment 0"? the shell. corresponds with the position oi? thepartition i instead of beingabove this pi as is 'ti'tion the case whenthe diaphragm 5 13 is used.

The diapliragg'ms may be constructed in various ways and of variousmaterials. it being" essential, however. llia i they be capable ot \rilnc ndiiuy the 'lfurnavi. icing-aeratures. It desirable also that they beformed wholly nirtiv oil; lliSllliltlllif ma l 1 I i rcrial -o reuuveneat lllllllili .is shown 1-! inc d'i'au'i :llx dial.ua. 3;in:;:. andthe cow l lii.HL1Hli wir-iisls' o a p "lo! il ni l. ll'zillll both latincement and lire z-lay. or terial. 'llie itlalinr .na erit" through theperl oratioiis in well as around the c og es of that the layers of itupon opposite sides the frame are securely bender. togeth in shelltreating furnaces he"eto"ore u: it has been customary to support l Ll1.,440, see

" to eliminate this ditliculty by providing nose of the shell.

means for engaging the shell thus accurately determining, its verticalposition in theturnace. In the embodiment shown in the drawings, themeans for determining the Vertical position of the shellfcomprises anadapter 44 which is located in the upper portion of the water receptacleThe water receptacle 21 contains passages providing for a continuouscirculation of the water containedin it, and is in general similar tothe receptacles which have herej-tofore been used in furnaces of thiskind.

from such receptacles'in that three recesses In the forin shown in thedrawings it ditiers 4:6 are formed in. the portion of its upper 'edgewhich is-within. a flange L7. The

adapter 44 has a frusto-conical hody 45. It isprovidedat its top withthree outwardly eted to he seated in the recesses 46 of the recep tacle21 so as to suspend the adapterin the u) er ortion oi"? the rece jtacleas shown in Figs. 2 and 3. Theinner surface of the adaptcr'is providedwith a plurality of inwardly extending upper projections 4.19 and aplurality of inwardly extending lower projections 50. 'The inner edges51 of the projections 49 and are so formed that they all enga e at thesame time the ogira-l portion of a shell'lowered into the receptacle 21.The adapter thus serves to eng e and support the shell during the drawntreatment with exactly the desired portion of its nose immersed, int-hewater of the receptaclo. The arrangement of the adapter is such that itdoes not interfere with the circulation of the Water in the receptacleabout the Separate adapters may he I prorided for each size of shell tohe trcatedin the furnace." These ada fiters are all similar to theadauter 4 lcxceot for variations in the l leii ths of theprojections 49and and the of :he inn surfaces 51. (,rt these projectionswhich are madeto en ble them to fit the shells'ol? different sizes.

The operation and use oi the furnaces.

such heatin It is desirable to, remove the out by means of it. Furthinn" in ward c osely around ".s-iired temperature may ace during theheating of numhei of shellst'or hardening, each shell being lowered tothe position indicated in Fig. 2 for water receptmtle 21, from theFurnaceduring such heating. v

For the drawing or tempering. treatment of the shell, it is desirable tosubstitute a diaphragm such as the diaphragm-25 of Figs. 3, 8 and 9 forthe diaphrag; to remove the diaphragm 25 the diaphragms 26 and must hefirst removed,

and they are replaced after the diaphragm,

The use oi the furnace described is by no' means limited to hardeningand drawing trc nenl as various other sorts of heat tree ient of variousarticles maybe carried H lore, we wish it clearly understood thatoutinvention is hy no means limited to its application to the ticult )eof t'urnace in. connection i h which hasheen described for theinyentionmay he incorporated in dili'erential treatment tiii'nacos oi?other types.

i i hat cl nied is:

l. in a c crentiul heating furnace, the cwnhination o a treating:chinnher, a dia- *end m inwairlly from the wall .1210. having an inneredge 1 .i :tend close to the surface of the object tohe treated. andmeans for supplyheat to the zones formed in said chamher by s idiaphragnn wherehya desired temperature. may he maintained in each zone.t

2. in a diterential l'ieating furnace, the

coinhii'iatioiz "with. a cylindrical. heating chamber of an annulardiaphragm eXtendtron? l he wa ll i said chamber finer edge :i-clapted toextend lie olxicct to he treatedv and means "for supplying; heat to theZOIRS termed in said chamber hysaid diaphragm, whci'chw' and having ltbrernti al llLd ting; inri'mce tl'io a it '19 chamber ind a outer a ("Inpted to en and an inner adap to extend close to the ohiel-t to heheated. and means for s:i'pglyiue heatto the zones formed in the chamberby said diaphragm. whereby (lellQ- maintained -h zone, L in a GINadapted to engage the wall 01 sai-dtreating In order desiredtemperaturemay hemain- "tamed in each mnc. i

aid chaniher,

difiei'ential heating furnace a i treating chamber a removable diaphragmin said treating chamber having 11 outeredgge i so provided at itsperiphery with means for supporting it inthe treating chamber of thefurnace.

15. A zoning diaphragm for use in a differential heating furnace,comprising a per-' ing a treating chamber, the combination of gage theobject to be treated and to deterv a plurality of annular diaphragmsarranged in spaced positions in said chamber and each adapted closely tosurroundthe object to be treated, and engaging means in the chamberadapted to engage a surface of the ob ject and to determine its positionwith respect to said diaphragms.

17. In a differential heat treating furnace having a treatingchamber anda liquid receptacle at the bottom thereof, an adapter removably seatedin said receptacle'having spaced projections. located below the level ofthe liquid in said receptacle adapted. to enmine the extent to whichsaidobject is inserted in the receptacle while permitting a free circulationof the liquid in said receptacle about the portion of the objectsubmerged inthe liquid.

18. In a differential heat treating furnace having a treating chamberand a liquid receptacle at the bottom thereof, an adapter insaidreceptacle having spaced internal projections formed to engage thecgival portion of a she'll-inserted in the treating chamber and todetermine the extent to which said shell is inserted in said receptaclewhile permitting a free circulation of the liquid in said receptacleabout the nose of the shell.

19. In a furnacehaving atreating chamber, the combination of an annulardiaphragm at the top of said chamber containing a central opening topermit the insertion of a shell in the chamber, and a divided coverplate seated upon said diaphragm and covering the opening ther in toprevent substantially the escape of heat from the treating chamber. i

In testimony whereof we have hereunto set our hands in the presence oftwo subscribing witnesses.

FREDERICK C. LANGENBEBG. JOHN F. FETTERLY. l/Vitnesses:

" JOHN G. SOLBERG,

R. H. WEBBER.

